Gas-furnace



(N0 Modl.) J. vZEL-LWEGER. 2 Sheets-Sheet 1..

' GAS FURNACE.

No. 409,090. Patented Aug. 13, 1889.

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- WITNESSES:

M rs (No Model.) 1 J. ZELLWEGER. 2 Sheets-Sheet 2.

GAS FURNAGE.

No. 400,000. I Patented Aug. 13, 1889.

WITNESSES l/VI/E/VTOR mafia. d i gy imavfiflw B A ron/ms UNITED STATES PAT T OFFICE.

JOHN ZELLVVEGER, OF CHICAGO, ILLINOIS.

GAS-FURNACE.

SPECIFICATION forming part of Letters Patent No. 409,090, dated August 13, 1889.

Application filed December 19, 1887. Serial No. 258,340. (No model.)

To whom it may concern.-

Be it known that 1, JOHN ZELLWEGER, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Gas-Furnaces, of which the following is a full, clear, and exact description.

The present invention relates to that class of gas-furnaces in which the ports for the inlet of the gas and air and the outlet for the products of combustion all communicate with the combustion-chamber from the same side thereof, the inlet-ports being at ahigher level than the outlet-ports, so that what is known asa return-downdraft is produced.

The objects of the said invention are, primarily, to increase the efficiency of such f urnaces, and, secondarily, to secure greater compactness in their construction.

The said invention consists in certain features of novelty, which are hereinafter particularly pointed out in the claims, being first fully described with reference to the accompanying drawings, in which are represented several furnaces embodying the said invention under as many different modifications.

Figure l is a view showing a section of the simplest and preferred form of the improved furnace in the vertical planeindicated by the line 1 1, Figs. 2, 3, and 4t, lookingin the direction of the arrows. showing sections thereof in the vertical planes indicated by the lines 2 2 and 3 3, respectively, Fig. 1, looking in the direction of the arrows. Fig. 4 is a view showing a section thereof in the horizontal plane indicated by the line 4 4:, Figs. 1, 2, and 3, looking downward. Fig. 5 is a view showing a section'of a fragment thereof in the horizontal planes indicated by the line 5 5, Fig. 1, looking downward. Figs. 6 and 7 are views showing sections of the improved furnace under a slight modification, in the vertical and horizontal planes indicated by the lines 6 6, Fig. 7, and 7 7, Fig. 6, respectively, looking in the direction of the arrows. Figs. 8 and 9 are views showing sections of the improved furnace under another modification, in the vertical planes indicated by the lines 8 8, Fi 9, and 9 9, Fig. 8, respectively, looking in the Figs. 2 and 3 are views direction of the arrows. Figs. 10 and 11 are views showing sections of the improved furnace under still another modification, in the vertical planes indicated by the line 10 10, Fig. 11, and 11 11, Fig. 10, respectively, looking in the direction of the arrow. Fig. 12 is a view showing a fifth form of the improved furnace in the vertical plane indicated by the line 12 12, Fig. 16, looking in the direction of the arrow. Figs. 13 and 14 are views showing sections thereof in the vertical planes indicated by the lines 13 13 and 14 14, respectively, Fig. 12, looking in the direction of the arrows. Figs. 15, 16, and 17 are views showing sections thereof in the horizontal planes indicated by the lines 15 15, 16 16, and 17 17, respectively, Fig. 12, looking downward. Fig. 18 is a view showing a sixth form of the improved furnace in the vertical plane indicated by the line 18 18, Fig. 20, looking in the direction of the arrow. Fig. 19 isaview showing a section thereof in the vertical plane indicated by the line 19 19, Fig. 18, looking in the direction of the arrow. Figs. 20 and 21 are sections thereof in the horizontal planes indicated by the lines 20 20 and 21 21, respectively, 18, looking downward.

The producer is not shown in some of the figures of the drawings, for the reasons that, so far as the present invention is concerned, it is entirely immaterial whether one be attached or not, and if one be attached it may be of any desired construction and locatedin any desired place. In those figures where one is shown it is indicated by the letter X.

A A represent the end walls, B B the side walls, and O the roof or ceiling, of the furnace proper, all of which maybe of masonry or any other suitable or desired construction.

The term furnace-chamber is hereinafter employed to designate all of that space which is situated between the walls A, A, B and B, the ceiling C, and a floor constituted of the two practically-horizontal partitions F and L, which are constructed at different elevations and united by a scarp. In some forms of the furnace a certain discrepancy in number between the ports which communicate with the furnace-chamber for the inlet of gas and air, respectively, renders it necessary to construct within said chamber a vertical partition L,which subdivides itinto two spaces, one of which F is hereinafter called the combustion-chamber, because within it the major part of the combustion takes place, and the other of which is called the airchamber, because its principal office is to control the admission of the air to the combustionchamber. As a matter of fact, combustion commences the instant the gas and air come in contact, and in every form of the furnace this takes place the instant the gas leaves the port 11). As will more fully appear hereinafter, this eontactof.the gas and air and consequent combustion exists throughout the entire space designated as the furnace-chamber, including the parts called the combustion-chamber and air-chamber, in all the various forms of the furnace excepting those shown in Figs. 8 to 11, inclusive. Air-cham; her and eombustion-chamber are therefore simply names, more or less arbitrary, employed to designate different parts of a chamber for the whole of which the name combustion-chamber might appropriately be employed, especially in those forms of the furnace from which the partition L" is entirelyomitted. This partition L is provided with ports L', of: the number, size, and location which circumstances mayrcquire, (hereinafter explained.) and which place the two parts F and L of the flirnace-chamber in direet communication.

The articles to be treated are placed within the part F of the furnace-chamber or the comlnistion-chamber, to the interior of. which access is had through one or more openings F formed through any of its walls and closed by suitable doors. The part.- l of the floor ot the furnace-chamber will therefore be seen to constitute the hearth, or the support for the article to be treated.

The gas from the producer or other source enters the furnace-chamber at one end thereof and is met by currents of heated air from the recuperator, with which it is thoroughly incorporated more or less quickly, according to the nature of the flame which it is desired to produce, as presently described. During the development of the flame the gas and air pass through the combustion-chambcr in a downward returning current, and thence, after combustion has taken place, the products of combustion pass through short ports G directly into the lire-tines ll. of the recuperator, whence they pass into the smokeiiue I through ilues J, all as shown by the feathcrless arrows.

The recuperator consists of the vertical fire-fines it and the vertical airh ues K, which are arranged in proximity to each other and preferably alternately, as shown, being sep arated only by partitions constructed of such material and of such thickness (preferably Very thin) as to otter a minimum resistance to the transmission of the heat from the products of combustion escaping through the tines II to the air in the ilues K, whereby the said ai r becomes highly heated, and ascending passes into the furnace-chamber through ports K, formed through the portion L of the floor thereof. It will be seen that these ports K are vertical and situated beneath and in proximity to the horizontal gas-inlet port D, so that the heated air will be introduced into the furnace-chamber beneath and in a direction at right angles to the horizontallyentering volume of gas.

The iiues ll and K of the recuperator have been spoken of as vertical, but I desire to have it understood that it is not essential that they be absolutely so. The object is to utilize the entire ascending force of the heated air for injecting it into the combustion-chamber, and this object will be accomplished the better the nearer the air-tines approach vertieal posit-ions; but practically an unobstructed upright or substantially vertical flue sufficient, and such a one (as distinguished from a serpentine flue or horizontal or vertical chamber with fire fines or tubes extending across it) is meant by the term vertical ilue as used in this specification.

It will be observed that the fire-Hues ii and air-fines K are situated entirely within the walls of the furnace and beneath the floor of the furnace-chamber, or, more specifically, beneath the portion L of said iloor which is slightly above the portion F which forms the hearth. Thence the said air-ilues extend downward to a level far below said hearth, where they communicate with the external atmosphere. This communication may be either direct or through the medium of ports N and tine N and air-space M, the latter being in direct connnunication with the atmosphere. The space M is situated directly beneath the hearth F, and its object. is to keep said hearth cool by carrying oil. the superfluous heat. The iire-fi ucs ll are equal in number to the outlet-ports (1, and one of: said flues con'imunicates at its upper end with each of said ports, the latter being very short and situated horizontally and beneath the floor l) of the air-chamber L, communicating with the combustion-chamber I1 slightly above the hearth. I The etlicieney of the furnace is greatly increased by this direct connection between the combustioirchamber and the lines, which brings the products of combustion into contact with the air-fines immediately upon their leaving the combustionchamber, it being manifest that if the the tines of the recuperator were situated at a distance from the outlet-ports of the combustion -chamber the products of combustion would lose much heat in passing from one to the other. The efliciency ot' the furnace is further increased by continuing the air-lines upward to the level of the ports K, through which heated air is discharged into the furnace-chamber, it being manifest that it said ilues terminated at a distance from said ports much heat and in many instances ascending force would be lost during the passage of the air from the former to the latter. The efficiency of the furnace is still further increased by making the adjacent air and fire flues c011- terminous, (or practically so,) so that from the time the products of combustion leave the combustion-chamber until they enter the smoke-flue they are giving up heat to the air in the air-fines; and at the same time, from the instant the air enters the air-flues until it is discharged into the furnace-chamber it is absorbing the heat yielded up by the products of combustion escaping through the fire-flues H. This arrangement is also important in that it renders the furnace much more compact than if the recuperator were situated at a distance.

It is desirable to spread out the air as much as possible as it passes through the recuperator, so as to increaseits superficial area, and thus bring it into contact with a maximum area of highly-heated surface in order to bring it to a high temperature more quickly than if it were passed through the recuperator in a compact volume. This I prefer to accomplish by employing a number (any number from one up) of narrow flues K, through which the air passes and from which it escapes through as many ports K.

It is manifest that if no means were employed to prevent it, the air, following the direction of the draft,would pa'ss directly to the end of the furnace-chamber opposite the end where it entered (t. 6., to the comb ustion-chamber) by the shortest and most direct route. This would not be objectionable in furnaces of the forms shown in Figs. 12 to 20, inclusive, and in which the gas enters in a very widely expanded or diffused state; but for some purposes it is desirable to have the gas enter in a more solid or compact volume, as it will in the furnaces shown in Figs. 1 to 11,inclusive. In such a furnace, if no means were employed to prevent it, the air escaping from those ports K which are remote from the gas-port D would pass, as described, directly to the combustionchamber without becoming commingled with the proper percentage of gas. In order that this may not result where the gas-port (or ports) is (or are) confined in ahorizontal direction within a narrower area than are the air-ports K, the wall or partition L is built across the furnace-chamber, forming the airchamber L, as already described. The purpose of this chamber L is to collect the air issuing from all the air-fines K and discharge it into the combustion-chamber in proper relation to the entering volume of gas. It will be seen that said air-chamber, and also the port. or ports through which the air escapes from it into the combustion-chamber, are situated entirely above the air-flues K. This is important, because otherwise more or less of the ascending force of the heated air would be lost.

The number, size, or location of the ports L" may be varied, according to the nature of the flame which it is desired to produce,

.slight mingling of gas and air as the former and the nature of the flame should be determined by the use for which the furnace is intended.

I will now fully describe and point out the differences between the several furnaces shown in the drawings and give the reasons for the variations.

The return-downdraft is common to all of the various furnaces shown in. the drawings. It is produced by locating the ports for the inlet of the gas and air and the outlet of the products of combustion all on the same side of the combustion-chamber, the outlet being at a lower level than the inlet. As furnaces having this arrangement of ports are known, it is not necessary to particularly set forth in this specification their principle of operation or their superiority over furnaces of other constructions.

The present invention relates more especially to the particular construction and arrangement of the recuperator in combination with such a furnace-chamber, and to the number, size, and location of the several ports.

In the furnace in its preferred form (shown in Figs. 1 to 5, inclusive) but a single port I) for the inlet of gas into the furnace-chamber is employed, and consequently the partition L is built across said chamber and provided with but a single port L. The port L' is of somewhat larger area than the port D, and the latter is situated directly opposite the bottom part of the former, so that nearly the entire volume of gas (which ,is introduced under pressure) passes directly through the lower part of said opening L (without coming in contact with the partition,) leaving the upper part thereof for the passage of air from the chamber L to the chamber F. The passage of the air through this port L" will not be confined entirely to the upper part thereof, for the reason that the volume of gas passes directly through the volume of air in chamber L, and will therefore induce more or less air on allsides. The volume of gas passing through chamber L and port. L is en vcloped with a thin sheet of flame, as a result of a passes in a compact volume or jet through the latter.

The furnace shown in Figs. 0 and 7 differs from that shown in Figs. 1 to 5, inclusive, in nothing excepting that in the former the various parts of the latter are duplicated, so as to produce two flames instead of one. In other words onehas two burners while the other has but one. A burner is a singleport or a plurality of ports arranged in proximity to each other for injecting in proper relations to each other the proper proportions of gas and air into the combustion-chamber.

The furnaces shown in Figs. 8 to 11, inclusive, differ from those shown in Figs. 1 to 7, inclusive, in that in the former the gas is not delivered into the air-chamber L, but is carried through it by a short flue forming a continuation of the port D, and delivered into ICO the combustion-chamber, where it meets for the first time the air from the recuperator, which escapes from the air-chamberinto the combustion-011amber through the customary port or ports If.

The furnace shown in Figs. 10 and 11 differs from those shown in Figs. 1 to 9 in that in the latter the ports L formed through the partition-wall L for the passage of air into the combustion-ehamber are equal in number to the ports D for the inlet of gas, and said air-ports are situated directly over said gas-ports, while in the former two of such air-ports Lare employed for each gas port, one situated upon each side thereof.

The furnace shown in Figs. 12 to 17, inclusive, diii'ers from all the others in that it has not the partition L in any formthis because the condition which renders said partition necessary is entirely wanting. A plurality of gas-inlet ports are employed and distributed in a horizontal direction over as wide an area as are the vertical air-ports K, said gas and airports being situated in proximity. The vertical planes of the gas-ports intervene the vertical planes of the air-ports, so that the vertically-entering aircurrents pass upward between the horizontally-entering gascurrents and strike the roof of the furnace-chamber, whereby said air-jets are scattered and the air commingled with the gas more quickly than in the forms of the furnace already described.

The furnace shown in Figs. 18 to 21, inclusive, has but a single gas-inlet portD, but this one extends the entire width of the furnace-chamber, so that the is introduced in abroad sheet-like jet. Here the gas enters in a solid sheet entirely above the air, and the latter is thrown forward toward the combustion-chamber in a direction almost parallel to the gas by a horizontal partition or deflector (1, which projects from the end wall A over the ports K, being supported by piers a risin g between the said ports. These conditions are such that, without some means to promote it, there would be but little tendency on the part of the gas and air to mingle, and as a consequence the latter (taking the most direct course) would fall directly upon the hearth with bad results. The air must therefore be controlled by the partition Ii; but owing to the fact that the port L through this partition for the passage of the gas to the co1nbustion'ehamber nmstbe coextensive with the gas-port I), said partition will be re duccd, in eliect, to a simple wall which does not extend entirely to the ceiling of the furnace-chamber.

When the gas-jet and air-jet are situated one above the other, a deflector Z is placed in the path of the one which is lower fordiverting it upward and causing it to intersect the other.

To recapitulate: In the furnace shown in Figs. 1 to 7, inclusive, the volumeof gas enters the comlmstion-chamber in a single j ct, surrounded to a greater or less extent by air, although the greater portion of the latter enters above the former. In the furnace shown in Figs. 8 and 9 asingle jet of air and a single jet of gas enter the combustionchamberseparately, the former entering directly above the latter. In the furnace shown in Figs. 10 and 11 a single jet of gas and two jets of air enter the combustion-chamber separately, all in the same horizontal plane, one jet of air upon each side of the jet of gas. I11 the furnace shown in Figs. 12 to 17, inclusive, the gas and air both enter in a plurality of jets. In the furnace shown in Figs. 18 to 21, inclusive, each enters in a single sheetlike jet, the gas above the air. Other combinations or arrangements of these parts are within the scope of my invention.

The purpose for which the furnace is intended should determine the nature of the flame which is to be produced and to produce flames of the various kinds required in the arts in which these furnaces are used is the object of these various styles of burner-- arrangements of ports for the introduction of gas and air. In comprehending 110w the different effects are produced itshould be borne in mind that combustion cannot take place until the gas is mixed with the proper proportion of air; hence the rapidity of combustion depends upon the rapidity with which this mixing of the gas and air is accomplished. The direction in which the gas and air meet influences the rate of combustion but only in so far as it affects the area of contact between them or their intermingling, as it is upon this latter that the combustion depends more especially. Consequently by varying these conditions any desired effect may be produced. For example, in the furnace shown in Figs. 10 and 11 the separate currents of gas and air traverse the combustion-chamber parallel to each other, and until they reach the farther end of said chamber they have contact and mix only at their adjacent sides. hen they arrive at or near the farther end of the chamber, their integrity is destroyed, they freely commingle, and combustion takes place. This furnace is designed to produce the largest flame of all. To produce a shorter flame, it is simply necessary to bring about the connningling of the gas and air at an earlier period. In the furnace shown in Figs. Sand 9) this is accomplished by placing the deflector Z in the path of the gas-jet for diverting its course from parallelism with the air-jet and causing them to intersect. To further reduce the length of the flame, the gas and air are introduced into the colnbustion-chamber through one and the same port, (see Figs. 1 to 5, inclusive,) and in addition thereto the deflector Z is placed in the path of the gas-jet proper for causing it to intersect the air. To still further reduce the length of the flame, the air and gas are spread out into broad sheets and introduced into the combustion-chamber in intersecting planes,'as shown in Figs. 18 to 21, inclusive. The furnace which produces the shortest flame of all is the one shown in Figs. 12 to 17, inclusive, in which the gas and air enter the combus- Lion-chamber at right angles to each other and each through a plurality of ports arranged in alternating planes, as described, so that the line air-jets pass upward between the fine gasjets and strike against the ceiling of the combustion-chamber, whereby the air is still more scattered and mixed with the gas.

As the length of the flame is decreased, so, also, should the length of the combustionchamber be proportionately decreased; hence in the-furnaces shown in Figs. 12 to 2-1, inclusive, the end wall A is so placed with relation to the opposite end wall A of the furnace-chamber as to reduce that part of the combustion-ehamber through which the flame passes downward to a simple contracted flue or passage. 'It will be observed that this contracted portion of the combustion-chamber is of smaller area than that portion in which the and then crowd the flame at that stage where combustion is most violent into a space of smaller area, so as to concentrate it, make it more intense and effective for such purposes as welding. The difference between the combustion-chamber here shown and that shown in the other figures is due simply to a change in the position of the end wall Aa difference in dimensions rather than anything else.

For welding purposes the furnace is further modified by forming the opening F through which the article to be heated is introduced, through the wall of the contracted portion of the combustion-chamber, thus enabling the articles to be thrust directly into the concentrated portion of the flame between the inlet and outlet ports, whereby they are more completely enveloped by said flame, and therefore more quickly heated than if they were allowed to rest upon the hearth.

The production of a return-downdraft re quires that the gas and air be introduced under pressure. The gas-pressure may be produced by the ascending force of gas from a source situated at a lower level than the combustion-chamber, or by a blast into the producer, or by pressure on a storage-vessel, or in any other desired manner. The airpressure maybe produced otherwise; but one of the principal objects of the present invention is to obtain the desired result from the recuperator unaided by a separate blast or pressure apparatus of any form. For the ef fective working of the furnace the pressure within the combustion-chamber should be sufficient to force the flame out at the furnacedoors (thus excluding cold air at these points) and through the outlet-ports, thus preventing stack draft or suction within said chamber.

By extending the vertical air-flues of the-recuperator from a level above the hearth (the level of the outlet-ports, the level of the combustion-chambeig) to a level far below the outlet ports, (the hearth,) where they receive their supply of air, and by subjecting them throughout their entire length to the heat of the escaping products of combustion, which pass downward through flues arranged in proximity to said air-fines and substantially eonterminous therewith, and by connecting the upper ends of both the air-flues and the fireflues of the recuperator directly with the furnace-chamber by means of very short flues or ports, the air in said air-Hues becomes so intensely heated, acquires such a powerful ascending force and meets with so little resistance, so direct and unobstructed is its passage to the furnace-chamber, that it enters the combustion-chamber under sufflcientpressure to force the flame out at the cracks around the doors and out at the outlet-ports, far down into the fireflues, thereby effectually preventing any suction within the combustion-chamber. In fact, the force of the blast produced by the ascending hot air in the recuperator is so great that its effect is present even for some distance down within the fireflues. The admission of cold air to any part of the combustion-chamber is thereby rendered impossible.

In actual practice it is found that where the ports for the inlet of gas and air are less in number than the ports for the outlet of the products of combustion, or said outlet is otherwise distributed in a horizontal direction over a wider area than the inlet, the tendency is for the products of combustion taking the nearest and most direct route to escape through the outlet-port which is nearest the inlet. To avoid this, the outlet-ports which are situated nearest the inlet-port are of smaller area than those more remote,.their sizes being gradually increased in proportion to the distance.

P represents a vertically-elongated rib or ridge extending horizontally into the combustion-chamber from the end opposite the inlet-ports, and which is hereinafter called a distributer, its object being to scatter the flame before it commences to traverse the combustioirchamber toward the outlet-ports and distribute it evenly and uniformly over the entire width of said chamber.

It will be observed that the flue N for supplying the recuperator with air is situated above the flues J, which carry off the products of combustion. The object of this is to heat the air at as lowa level as possible in order that it may have a greater ascending force, the heating being facilitated by placing the heat-flues beneath the air-flues, so that the latter may not be chilled by or take up damp vapors from the ground. These flues J and N are separated only by thin sheets of metal or fire-tile.

I desire to have it understood that while it is preferred to construct the recuperator of vertical fines, yet, so far as certain features of my invention are concerned, it is immaterial what the number or positions of said fines may be.

I am aware that furnaces having ports so arranged as to produce a return-downdraft are old also, that reeuperators having vertical air and fire fines arranged in proximity to each other are old; also, that reeuperators have been situated both below the level of the combustion chamber and connected therewith by fines and on the same level as said chamber. I do not claim any of these things per 30 as n'lyinvention.

Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

1. In a gas-furnace, the combination, with the furi'laee-chamber having ports for the inlet of gas and air and outlet of the products of combustion, all connnunicating therewith from the same side thereof, of a recuperator having unobstructed vertical air-fines extending from a level above the hearth downward, terminating and communicating with the atmosphere at a level below said hearth, and the fire-fines communicating with the ports for the outlet of the products of combustion and extending downward therefrom in proximity to the air-fines, substantially as set forth.

2. In a gas-furnace, the combination, with the fui'nace-chamber having ports for the inlot of gas and air and oulet of the products of combustion, all connnunicatin g therewith from the same side thereof above the level of the hearth, the inlet above the outlet, of a recuperator having an unobstructed vertical air-fine communicating at its upper end with the air-inlet port and extending from the level of said port downward, terminating and communicating with the atmosphere at a level below said hearth, and a fire-fine communicating at its upper end with the port for the outlet of the products of combustion and extending from the level of said port downward in proximity to the air-fine to a level far below the hearth, substantially as set forth.

. In a gas-furnace, the combination, with the furnace-ehamber having ports for the inlet of gas and air and a plurality of ports for the outlet of the products of combustion, all communicating therewith from the same side thereof, of a recuperator having unobstructed vertical air and fire fines located in proximity to each other and extending from a level above the hearth downward to a level far below it, said fines communicating at their upper ends with the ports for the inlet of air and outlet of product-s of combustion, respectively, said outlet for the products of combustion being horizontal, substantially as set forth.

4. In a gas-furnace, the combination of the furnace-chambcr having a horizontal inlet for the gas, a vertical inlet for the air, situated beneath and in proximity to the gas inlet, an outlet for the products of combustion, and a recuperator communicating with the external atmosphere directly and with said air-inlet for supplying the latter with heated air free from gas, substantially as set forth.

5. In a gas-furnace, the combination, with the furnace-chamber having a horizontal port for the inlet of gas and a horizontal port for the escape of the products of combustion communicating therewith from the same side thereof, of a recuperator having vertical airlines terminating at. their upper endsbeneath and in proximity to the said gas-inlet, and fire-fines separated from said air-ll ucs only by thin partitions and communicating at their upper ends with the horiztmtal outlet-port, said air and fire fines extending from the levels of the ports with which they respectively communicate downward, terminating at a level. far below the hearth, eommunicatingat their lower ends with the atmosphere and smoke-flue, respectively, substantially as set forth.

6. The combination, with the furnacechamber having a port for the inlet. of gas and a port for the outlet of the products of combustion, of the air-fines K, communicating at top with said chamber, the line N, comnnmicating with said air-flue at bottom, the lire-lines II, also communicating at top with said chamber, and the fines J, communicating with said fire-flues at bottom, the lines I being situated beneath the tines N and separated therefrom only by thin partitions, substantially as set forth.

7. I11 a gasfurnace, the combination, with the co1nbustion-chamber, of an air-chamber, a recuperator having a plurality of air-lines all communicating with said ail-chamber, a port opening into one side of said chamber for the admission of gas, and a port directly opposite said gas-inlet, forming communication between said air and eombust-iomchambers, and through which the gas from the gasinlet port passes directly into the combustionchamber without striking against the walls of the air-chamber, as set forth.

8. In a gas-furnace, the combination, with the eombustion-chamber, of an air-chamber, a port forming comnumication between said chambers, a recuperator having vertical airfiues communicating with said air-chamber through openings in the floor thereof and ex tending downward therefrom to a level far below the hearth, fire-fines located in proximity to said air-fines, and horizontal ports situated beneath the fioor of the air-chamber and forming communication between said fire-fines and the combustion-chaml)er, substantially as set forth.

9. In a gas-furnace, the combination, with the furnace-chambcr, of thepartition1/,scparating it into combustion-chamber F and ISO rality of ports opening directly from said tanee from the inlet, substantially as mid for chamberfor the outlet of the products of comthe purpose set forth.

bustion, said outlet bein situated on the V 1 same side of the eomb'usti on-chamber as the JOHN ZELL EGER' inlet but distributed in a horizontal direeitnesses:

izion over a wider area, the sizes of said out- L. M. HOPKINS,

let-ports increasing in proportion to their dis- WV. \V. ELLIOTT.

air-chamber L, the port L, formed through said partition and connecting chambers F and L, the port D, opening into the chamber L directly opposite the port L', and a recuperator communicating with the chamber L, substantially as set forth.

10. In a gas-furnace, the combination, with the furnace-chamber having ports for the inlet of gas and outlet of the products of combustion communicating therewith from the same side thereof, the outlet below the inlet, of a recupcrator having vertical air-fines communieating at top directly with one of said chambers and extending downward therefrom to a level far below the hearth, where they ccnnmunicz'ite with the atmosphere, and the tire-fines separated from said air-fines only by thin partitions, said lire-lines communicating at top directly with each of the outlet-ports and at bottom communicating with the smokellue, as set forth.

11. In a gas-furnace, the combination, with the furnaee-ehamber having ports for the inlot of gas and outlet of the products of combustion communicating therewith from the same side thereof, of a recuperator having a series of vertical air-lines arranged beneath and extending downward from the floor of said chamber communicating with said chamber through ports formed through the floor thereof, and the lire-lines separated from said ai r-flues only by l hin partitions, substantially as set forth.

12. In a gas-furnace, the combination, with the f urnace-chamber having its floor formed at different elevations (F and L) and ports for the inlet of gas and outlet of the products of combustion communicating therewith, of a reeuperator having a series of vertical air and fire llues arranged beneath the floor of said chamber and extending downward there from, said air-fines communicating at their upper ends with said chamber through ports formed through the higher portion L of its floor and said fire-fines communicating with the ports for the outlet of the products of combustion, all of said ports being situated on the same side of the combustioirchamber, substantially as set forth.

1 In a gas-furnace, the combination, with the furnace-chamber having its floor formed at different elevations, (F and L,) ports for the inlet of gas and outlet of products of combustion eonnnunicating therewith from the same side thereof, said inlet being situated above the higher portion L of said floor and said outlet extending horizontally beneath said higher portion, of a recuperator having vertical air-fines situated beneath and extend ing from the portion L of said floor downward to a level far below the outlet and communicating at top with said chamberthrough ports formed through the floor L thereof, and the lirellnes eomnumicating at top with the ports for the outlet of the products of combustion and extending downward therefrom lines K eonnnunicate with the fnrnace-eham-' her, a plurality of vertical fire-lines .ll, also situated beneath the portion L of said floor, extending downward in proximity to-the airflues K and communicating at top with the ports for the outlet of the products of combnstion, and the partition L, extending across the furnace-chamber and having port 1/, substantially as and for the purpose set forth.

15. In a gas-furnace, the eombil'lation of a combustion-ehamber, a single port for the inlot of gas and air, and a plurality of ports for the outletof the products of combustion sitnated at a lower level than the i nlet-port but on the same side of the comlmstion-chamber, said outlet being distributed in a horizontal direction over a much wider area than that occupied by the inlet, substantially as set forth.

lti. In a gasfurnace, the combination of a combusticm-chamberhaving a gas and air inlet and plurality of ports for the outlet of the products of combustion, said inlet and outlet being upon the same side of the combustionchamber, a recuperator having air tines communicating with the inlet and having a plurality of fire-lines, one communicating at top directly with each of the outlet-ports, said air-fines and l'iredlues bein separated only by thin partitions and extending from a level above the hearth to a level .far below it, substantially as set forth.

17. The COIlllJlDLtlOl'l,\Vltll the combustionchamber having an inlet for and air and an outlet for the products of combustion, said inlet and outlet being situated on the same side of the combustion-ehamber, of a vertically-elongated distributer situated opposite the inlet for distributing the flame horizontally, substantially as set forth.

1b. In a gas-furnaee,the combination, with the combustion-chamber having inlet for gas and air and outlet for products of combustion, all situated on the same side thereof, the outlet being (llStllblltQtl in a horizontal direction over a much wider area than said inlet, of a verticallyelongated distrilmter placed opposite the inlet for distrilmting the flame in a horizontal direction over the entire width of the eoml)ustitm-chamber, substantially as set forth.

19. A gas-furnace having a combustionchamber, an inlet for gas and air, and a plu- It is hereby certified that in Letters Patent No. 409,090, granted August 13,1889, upon the application of John Zellweger, of Chicago, Illinois, for an improvement in Gas Furnaces, errors appear in the printed specification requiring the following corrections, viz In line/117, page 4, the word largest, should read Z012 gest, and in line 13, page 7, the Words one of should be stricken out and inserted after the Word partitions, in line 18, same page; also, the Word chambers in line 14, same page, should read chamber; and that the Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed, countersigned, and sealed this 15th day of October, A. D. 1889.

[SEAL] CYRUS BUSSEY,

Assistant Secretary of the Interior. Gountersigned: v

G. E. MITOHELL,

Ormmzisstmzer of Patents. 

